Pineal region neuroenteric cyst in a 13-year-old girl: A rare localization with postoperative recurrence and local dissemination.

Background: Neuroenteric cysts are rare cystic benign neoplasms of the central nervous system most often located in the spinal cord and rarely, intracranially. The nonspecific neuroimaging features make management planning potentially challenging. We present a case of a radiologically misdiagnosed neurenteric cyst with a complicated course. Case Description: A 13-year-old girl presented with a 6-month history of headache, tinnitus, and dizziness. Initial magnetic resonance images (MRIs) were indistinguishable from a pineal arachnoid cyst with aqueductal stenosis and hydrocephalus. Cyst fenestration was performed through an infratentorial supracerebellar approach. Histology revealed a neurenteric cyst. On day 10 postoperatively, she deteriorated with acute hydrocephalus and cyst enlargement. An external ventricular drain was inserted. She remained asymptomatic thereafter. At 1-year postoperative, the patient remains asymptomatic despite the MRI showing cyst enlargement and local dissemination in the form of multiple cystic lesions in the cerebellum along the operative corridor. The patient was managed conservatively considering adhesion noted intraoperatively. Conclusion: Neuroimaging features of brain cystic lesions may be nonspecific. Special attention should be awarded to posterior fossa and paramedian cystic lesions. Rarer lesions like neurenteric cysts should also be considered. When in doubt, we recommend using the following methods to prevent the free outflow of the cyst contents into the subarachnoid space: lining the cyst and operative corridor with cotton wool and puncture opening and suctioning of fluid. However, the "gold standard" remains surgical treatment with radical excision of the endodermal cyst capsule. It is necessary to preassess the possibility of total or subtotal resection.